This is the green Correct It pad, a vivid green foam disc with a centre hole, in the 135mm (5.5in) size. It is the polishing pad of the system, the step after the orange cutting pad.
Green is the soft polishing pad. Autobrite lists it for fine scratches, swirl marks, holograms and marring on modern paint, including hard German clear coat.
Correct It is Autobrite Direct's colour coded pad system for its DA-21mm and DA-12mm dual action polishers. The pads are made from German open cell foam. A hole through the centre lets air through to keep the temperature steady and helps line the pad up on the hook and loop backing plate, a denser foam layer cuts vibration and heat, and the bevelled edge keeps the backing plate away from the paint.
More in Medium Cut Foam Pads.